This study will examine the cancer experience of a set of mothers and their male and female offspring exposed to DES during the mother's pregnancies. The general method will be to identify cohorts of exposed persons and otherwise comparable non-exposed persons by reviewing prenatal records from cooperating Connecticut obstetricians and then to identify total cancer experience through the connecticut Tumor Registry. Differences between the diseased and non-diseased groups will be described in terms of exposure variables (dose, duration, time of initiation of treatment), age, sex of the subjects, and the cancer sites involved. BIBLIOGRAPHIC REFERENCES: Meigs, J. W. and Watman, F., "Risk of estrogens in obstetrics", Connecticut Medicine, 41:5, May, 1977.